Keyless chuck



July 25, 1944. A. M. STONER 2,354,226

KEYLESS CHUCK Filed June 26, 1942 y 2 Sheets-Sheet 1 ATTORNEY July 25,1944. STONER 2,354,226

KEYLESS CHUCK Filed June 26, 1942 2 Sheets-Sheet 2 ATTORNEY PatentedJuly 25, 1944 um Eo STATE.

KEYLESS CHUCK Arthur Merrick Stoner, West Hartford, Conn,

assignor to The Jacobs Manufacturing Company, Hartford, Conn., acorporation .of Con.-

' necticut Application June 26, 1942, Serial No. 448,558

' 6 Claims. (01. 279-33) This invention relates to keyless chucks, and

especially to chucks of the type shown in United States Patent2,207,230, issuedto me July 9, 1940, and its object is to provideimprovements over the chuck shown in that patent. In Patent 2,207,230, Ishowed that simultaneously rotatable eccentric clamping jaws of a chuckmay be micrometrically adjusted 'in' relation to the axis of the chuckby mounting them upon angularly adjustable posts which have portionsabout which the jaws rotate, which portions are eccentric to the axis ofthe mounting of the posts; together with means for locking the posts intheir adjusted positions. I have discovered that the advantage of theinvention disclosed in the aforesaid patent may be attained in the.novel manner disclosed herein, in which the posts upon which the jawsare rotatably mounted are used to hold the parts of the chuck together,and such of the posts as may. have eccentric portions are held in thedesired angular relation to the axis of the chuck by the act ofassembling the parts. This and other objects of the invention. will befully described in the following description and the novel features ofthe invention which will be set forth in-the appended claims.-

,Referring to the drawings, Fig. .1 is a sectional side elevation of apreferred form of chuck. which is made according to and embodies theinvention; a

Fig. 2 is'a front elevation of the chuck shown in Fig. 1; l

Figs. 3 and iare sectional end elevations of the chuck shown in thepreceding figures, the sections being taken respectively on the lines 33and. 4-4 of Fig. l; 1

Fig; 5 is an enlarged frontelevation of the clamping jaws, with theeccentric portions of the postsupon which they are mounted shown insection.

l8 designates the substantially cylindrical body of the chuck having afiat transverse face I I. I2 isan internally threaded vaxialbore in therear end of the body which is adapted to fit an externally threadedspindle of a machine .tool, such as a power. drill. I3 is an annulargroove in the body intermediate its ends. Fromv Figs. 1 and 3 it maybeseen that the front side .of this groove is a flat surface, but thatthe rear wall has an inwardly extending portion which forms. an abutmentmember M which makes a small part |3A of the groove narrower than therest of it. The purpose of this construction will be explainedhereinafter. i5, is a hole drilled inthe body in a direction parallel.with. the. axis -.of the body and in. such a position that itintersects the base of the groove.

Three post holes l6 are drilled into'the body from its outer face. Theseare equally spaced angularly and are at anequal distance from the axisof the body and parallel therewith. The inner end portions of these postholes are provided with internal screw threads l'|-.- Between the postholes are three equally spaced-dowel holes I8. Three circular pocketsI9, concentric with the post holes 16, are countersunk below the face llof'the body. a I 20 designates a hollow cylindrical sleeve rotativelysupported on the body. Thesleeveover-i lies the groove l3 and extendsto:the face Hiof the body. At its forward end it has an annular; ring ofgear teeth 2! and these teeth extend into. the pockets IS. A hole 22 isbored into the rear end of the sleeve parallel withitsi axis'andintersecting its inner surface. One end of a-flat spiral spring 23 ishooked into-the hole 22. The spring lies in the groove l3, and its otherend is hooked into the hole IS .in the body. This arrangement is such asto cause the sleeve M) to rotate on body I!) in ananti-clockwisedirection, as viewed from the front endof the chuck,(Figs. 2 and 4-).

The relative -movement of .the sleeve on the, body is limited by a.-stop:member 24 (Fig. 3)' which lies in the .groove I3 on the rearsurface of the wider part of the groove. The thickness of the stopmember is preferably the same as that of the abutment. 14, (see Fig.1),Ithas two prongs or forks 25, 26 which engage the abutment l4 and midwaybetween them-is an outwardly projecting lug 21 which extends into-a slotcut in the end of .the sleeve. Thesleeve may be rotated in the oppositedirection against the action of the spring by hand, by, the operatorgrasping its outer, surface which is fluted, as shown at 28,- tofacilitate such operation. I Bosts having cylindrical portions 30 arefitted into the holes IS. The inner end portions'of. thes postsarethreaded, as shown -at 3l, to fit the threads Conical heads,.32 areformed on the outer end of the posts in axial alinement with the parts36 thereof. 33. designates hexagonal wrench sockets for rotating the.posts.

Intermediate the portions .30 and the heads 32 of the posts arecylindrical parts 34 .upon which the clamping laws are rotatablymounted.- The parts 34 of one or more of the posts maybe slightlyeccentric to the portions 30 and the heads 32. .The heads of the postshaving eccentric parts 34 may be marked, asat 3 5, to indicate themaximum point of eccentricity.

Pinions 36, seated inthe pockets 19, are rotatively supported on theintermediate parts 34 of the posts. These engage and are driven by theteeth 2! of sleeve 20.

40 designates the clamping jaws. These have cylindrical bores 41 whichsurround the intermediate portions of the posts with interposed rollers42. Each jaw has a body with an eccentric portion 43 and with spacedeccentric ribs 44 which are preferably cut spirally, as shown in PatentNo. 2,207,238, issued to Charles Edward Clark, July 9, 1940. A socket 45is formed in the rear end of each clamping jaw and a lug 31 projectsfrom the hub of the adjacent pinion into this socket so that therotation of the pinions is transmitted to the clamping jaws.

50 designates a cover plate which is provided with clearance holes forthe hubs of the pinions 36 and for dowel pins The cover plate lies onthe face ll of the body and extends over the front end of the sleeve 20to retain it on the body.

50 is a nose piece in the form of a flat plate 6| with legs 62projecting inwardly therefrom to the cover plate 50. 63 are dowel holesin the legs. The dowel pins 5| are placed in these holes and in thedowel holes [8 in the body to insure the proper angular alinement of thebody and the ose piece. 64 designates conical openings in the plate 6|to receive the heads 32 of the posts. ere is also a central bore 65 inthe plate to lear a tool or other object to be held in the buck. Whenthe parts are assembled the clampng jaws 4!! lie between the innersurface of the late El and the cover plate 50. The rollers lie ugs 31a.

It is difficult to machine the parts with suffiient accuracy to insurethe positioning of the lamping jaws being such as to hold a tool or therobject in exact axial alinement with the xis of the shaft. In Patent No.2,207,230, I howed a mounting for the clamping jaws which an bemicrometrically adjusted to overcome this ifficulty. I have discoveredthat the desired reult may be attained by the simplified construcionshown and described herein. According to he present invention thesupports for the clampng J'aws consist of a body having a transverse atface, a nose piece comprising a plate spaced rom the face of the body byinwardly projecting egs and posts having concentric portions seated nthe body, heads concentric with such seated ortions, which heads engagethe plate of the ose piece and threaded ends which ar screwed nto thebody with parts intermediate the seated ortions and the heads, uponwhich parts the lamping jaws are rotatably mounted. Any one r more ofthese intermediate parts may be ecentric to thethreads and heads of itsrespective In assembling the parts, posts having concenric parts 34,such as shown at A in Fig. 5 are sed. It maybe found that one or more ofthe aws need a slight adjustment toward or away rom the axis of rotationof the chuck. In such ase, posts which have eccentric bearing portionsre substittued. For example, the post shown at in Fig. 5 may, whenscrewed up tight, have its oint of eccentricity at an angle b from aradius hrough the axes of the chuck and of the conentric part of thepost, in order to position its lamping jaw at the exact distancerequired from he axis of the chuck.

Similarly, the post shown at C in Fig. 5 may,

etween'the inner surface of plate BI and the ubs of pinions 36 andinside the projecting when screwed up tight, have its point ofeccentricity at an angle 0 from a radius through the axes of the chuckand of the concentric part of the post, in order to position itsclamping jaw at the exact distance required from the axis of the chuck.In this simple manner the supports for the clamping jaws may bepositioned with the greatest nicety.

The length of the legs 62 of the nose piece is important as itdetermines the exact distance between the plate 6| and the threads l1and permits the posts upon which th clamping jaws are mounted to holdthe nose piece, the cover plate and the body I0 together underconsiderable pressure without creating any longitudinal pressure uponthe sleeve 20, the pinions 36, the clamping jaws 40 or the rollers 42,so that all of these parts may rotate freely.

What I claim is:

1. A chuck comprising a rotatable body, a nose piece having a transverseplate, angularly spaced legs projecting from said transverse platearranged to space said plate from the body, posts having heads engagingthe plate and screwed into spaced threaded holes formed in the bodyparallel to the axis thereof to secure the nose piece to the body, saidposts having parts intermediate their heads and the portions thereof inthe holes in the body, eccentric clamping jaws between the body and theplate of the nose piece rotatably mounted on said intermediate parts ofthe posts, the intermediate part of at least one of the posts beingeccentric to the part thereof in the hole in the body, a sleeverotatably supported by the body, and means for causing the rotation ofthe sleeve on the body to impart a simultaneous rotation of the clampingjaws on said posts.

2. A chuck comprising a rotatable body, a nose piece having a transverseplate, angularly spaced legs projecting from said transverse platearranged to space said plate from the body, posts having heads engagingthe plate and screwed into spaced threaded holes formed in the bodyparallel to the axis thereof to secure the nose piece to the body, saidposts having parts intermediate their heads and the portions thereof inthe holes in the body, eccentric clamping jaws between the body and theplate of the nose piece rotatably mounted on said intermediate parts ofthe posts, the intermediate part of at least one of the posts beingeccentric to the part thereof in the hole in the body, a sleeverotatably supported by the body, and means for causing the rotation ofthe sleeve on the body to impart a simultaneous rotation of the clampingjaws on said posts, the length of said posts being so proportioned inrelation to said legs that when screwed up tight the axes of theintermediate parts of the posts will be brought into desired distancesfrom the axis of rotation of the body.

3. A chuck comprising a rotatable body having a reduced cylindricalportion and a transverse face, a cover plat seated upon said face andextending over said reduced portion of the body, a nose piece having atransverse plate and angularly spaced legs projecting from saidtransverse plate to the cover plate, posts having heads engaging thetransverse plate of the nose piece, passing through the cover plate andscrewed into spaced threaded holes formed in the body parallel to theaxis thereof to secure the nose piece and the cover plate to the body,said posts having parts intermediate their heads and the portionsthereof in the holes in the body, eccentric clamping jaws between thetransverse plate of the nose piece and the cover plate rotatably mountedon said intermediate parts of the posts, the intermediate part of atleast one of the posts being eccentric to the part thereof in the holein the body, a sleeve rotatably supported by the body back of the coverplate, and means for causing the rotation of the sleeve on the body toimpart a'simultaneous rotation of the clamping jaws on said posts.

4. A chuck comprising a rotatable body having a reduced cylindricalportion and a transverse face, a cover plate upon said face extendingover said reduced portion of the body, a nose piece having a transverseplate and angularly spaced legs projecting from said transverseplate tothe cover plate, posts having heads engaging the transverse plate of thenose piece, passing through the cover plate and screwed into spacedthreaded holes formed in the body parallel to the axis thereof to securethe nose piece and the cover plate to the body, said posts having partsintermediate their heads and the portions thereof in the holes in thebody, eccentric clamping jaws between the transverse plate of the nosepiece and the cover plate rotatably mounted upon said intermediate partsof the posts, a sleeve rotatably supported by the body back of the coverplate, means for causing the rotation of the sleeve on the body toimpart a simultaneous rotation of the clamping jaws on said posts, aspring arranged to rotate the sleeve in relation to the body in adirection to move the clamping jaws toward their gripping positions, andmeans for limiting the rotative movement of the sleeve in relation tothe body.

5. A chuck comprising a rotatable body, a nose piece having a transverseplate, means for spacing said plate from the body, posts having headsengaging the plate and screwed into spaced threaded holes formed in thebody parallel to the axis thereof to secure the nose piece to the body,said posts having parts intermediate their heads and the portionsthereof in the holes in the body, eccentric clamping jaws between thebody and the plate of the nose piece rotatably mounted on saidintermediate parts of the posts,

the intermediate part of at least one of the posts being eccentric tothe part thereof in the hole in the body, a sleeve rotatably supportedby the body, means for causing the rotation of the sleeve on the body toimpart a simultaneous rotation of the clamping jaws on said posts, aspring arranged to rotate the sleeve in relation to the body in adirection to move the clamping jaws toward their gripping positions, andmeans for limiting the rotative movement of the sleeve in relation tothe body, said means comprising a transverse stop member positivelyengaging the sleeve, said member having spaced prongs, and an abutmentprojecting from the body between said prongs in the plane of said stopmember.

6. A chuck comprising a rotatable body having a reduced cylindricalportion and a transverse face, a cover plate upon said face extendingover said reduced portion of the body, a nose piece having a transverseplate and angularly spaced legs projecting from said transverse plate toth cover plate, posts having heads engaging the transverse plate of thenose piece, passing through the cover plate and screwed into spacedthreaded holes formed in the body parallel to the axis thereof to securethe nose piece and the cover plate to the body, said posts having partsintermediate their heads and the portions thereof in the holes in thebody, eccentric clamping jaws between the transverse plate of the nosepiece and the cover plate rotatably mounted upon said intermediate partsof the posts, a sleeve rotatably supported by the body back of the coverplate, means for causing the rotation of the sleeve on the body toimpart a simultaneous rotation of the clamping jaws on said posts, aspring arranged to rotate the sleeve in relation to the body in adirection to move the clamping jaws toward their gripping positions, andmeans for limiting the rotative movement of the sleeve in relation tothe body, said means comprising a transverse stop member positivelyengaging the sleeve, said member having spaced prongs, and an abutmentprojecting from the body between said prongs in the plane of said stopmember.

ARTHUR MERRICK STONER.

